The present invention relates generally to ink curing apparatus and methods of handling large articles, such as 5-gallon pails to 55-gallon drums.
Various articles have labels or designs printed upon their exterior surfaces with ink which may be cured by exposure to infrared or ultraviolet radiation. Typical of such articles are large plastic containers, such as 5-gallon pails or buckets and other containers including 55-gallon drums. Because the printed matter on such articles frequently extends around the entire circumference of the article or is located at various locations about the circumference of the article, it is desirable that curing apparatus provide 360.degree. exposure to ultraviolet radiation for each article. In the past, some types of curing apparatus have included means for gripping container necks to support them and rotate them while transporting them past an ultraviolet lamp. While such apparatus may be satisfactory for use with necked containers, it may not be suitable for curing ink on large articles such as buckets which do not have necks.
Large articles such as five-gallon paint buckets or even larger barrels are difficult to handle. Most existing equipment is not, or can not be, adapted to cure such articles in an economical manner. U.S. patent application Ser. No. 548,207 filed Nov. 2, 1983 and assigned to the assignee of this application discloses an inexpensive and efficient apparatus to cure ink on such large articles.
In the handling of such articles, the exposure of persons to excessive amounts of ultraviolet radiation is undesirable. Thus, ultraviolet curing apparatus has an ultraviolet lamp enclosed within a housing for confining the radiation, and a turntable for transporting the articles past the lamp within the housing. The turntable may have a series of compartments each of which receives an article and is separated by compartment walls which allow loading or unloading of the articles without exposing any workers to the radiation.
In commercial printing operations, ultraviolet curing apparatus is commonly used in proximity to the printing equipment which deposits the ink on the articles so that the ink may be cured immediately after it is applied. It is desirable that the curing apparatus be capable of being loaded and unloaded with minimal labor as labor expenses add significantly to the cost of the printed article. Because the exposure time required to cure the ink on a particular article may be relatively short, it is most desirable to reduce the period of time required for loading an article and for transporting the article from an input location to the curing station and then to an output location for unloading the article with cured ink thereon. Often two persons are used with one person doing the loading and another person doing the unloading. There is a continuing demand for improvements in the handling of articles to increase the efficiency of curing operations and to reduce the labor costs associated therewith.